Rate of load change measuring instrument



April 25, 1950 D. J. DWYER 2,505,237

RATE OF LOAD CHANGE MEASURING INSTRUMENT 5 Sheets-Sheet 1 Filed Aug. 18, 1943 INVENTOR 7 'i-"rvr 4 ATTORNEY April 25, 1950 D. J. DWYER 2,505,237 RATE OF LOAD CHANGE MEASURING INSTRUMENT Filed Aug. 1a, 1943 3 sheets-sheet 2 J 5 J at? 6/ 3 27 6 i Iv! vvv April 25, 1950 D. J. DWYER RATE 0? LOAD CHANGE MEASURING INSTRUMENT 3 Sheets-Sheet 3 Filed Aug. 18, 1943 Patented Apr. 25, 1950 UNITED STATES TENT OFFICE RATE OF LOAD CHANGE MEASURING INSTRUMENT tion of Connecticut Application August 18, 1943, Serial No. 499,077

8 Claims.

This invention relates to the art of producing a direct-reading indication of measurable rates of change in a condition thereby, for example, to register automatically the rate at which a weighable load decreases or increases as a fluid or other flowable substance constituting such load enters or leaves a weighable container.

In the art of measuring rates of flow it is possible to take note of the interval of time that is consumed by the progressive travel of a weight indicating pointer over some observed portion of a scale of weight indicating graduations, and from the data so obtained to compute the rate of load change or the rate of flow of fluid out of a container of fluid being weighed. But this entails a separate, time consuming, laborious series of computations corresponding to each difierent use of the instrument before the desired rate of load change can be known and expressed in simple terms such as gallons per hour.

It is a principal object of the present invention to save the time and labor that would be consumed by the constantly required repetitious computations referred to, and to avoid human errors that are most likely to result from a practice of making extensive computations each time it is desired to know or record the rate of change of weight undergone by a Weighable lead over a given period of time or the rate of change which is undergone by any other variable condition that can be measured automatically by an instrument.

The present improvements aim to provide a rate meter involving a condition measuring instrument in which such instrument may continue its function of detecting progressive change that is taking place in some measurable condition, and in which meter at any time during the progress of such change of condition a marker indicator may be set in motion to perform an excursion of timed duration correlated to the detecting function of the instrument and may thereafter come to rest and remain stationary independently of the measuring instrument in a position registering the rate of change undergone by the condition during such excursion.

In one field of practical use, it is an important object of these improvements to provide weighing apparatus, inclusive of a register, wherein during the now of liquid lubricant to the bearings of different kinds of motors or engines, or during the consumption of liquid fuel fed to an internal combustion engine, the rate of such flow or oonsumption may be read without computation directly in terms of gallons per hour or in terms of any other desired units of liquid quantity per unit of time by reference solely to the attained stationary position of a single indicator.

These and other objects of the invention will become clearer from the following description of -a practical embodiment of the improvements,

which description has reference to the accom panying drawings wherein:

Fig. 1 is a front view of the dial head unit of a pendulum type of weighing scale and associated I instrumentalities embodying the present invention.

Fig. 2 is a side view looking from the right at Fig. 1 with the casing sections partly broken away to expose the load counterbalancing and rate of change registering mechanisms.

Fig. 3 is an enlarged detail of certain of the graduations and indicia roughly indicated on the face of the dial chart of Fig. 1.

Fig. 4 is an enlarged fragmentary view taken partially in section on the plane 4-4 in Fig. 1.,

Figs. 5, 6 and 7 show on a much smaller scale different positions of associated indicating pointers which sweep the dial of Fig. 1.

Fig. 8 is a diagram of circuit connections to the electrical part of the apparatus which appears in Fig. 4.

Fig. 9 is a perspective view of a complete weighing scale supporting a weighable container of outfiowing liquid whose average rate of outflow is to be registered by the improved ways and means hereof.

Fig. 10 is a diagrammatic view of a manually set interval timer with its time controllable switch conditioned to energize the declutching solenoid.

Fig. 11 is a similar view of the time controllable switch conditioned to energize the clutching solenoid.

In Figs. 2 and 4 there is a general disclosure of the dial head of a weighing scale which in detail may be like that more fully disclosed in U. S. Patent No. 2,083,413 granted to G. E. Weist. This dial head may consist of a casing 56 whose hollow throat H is perched to swivel about a vertical axis on an underlyingcabinet or standard and may carry the dial chart i'i marked with weight designating indicia lB' swept by weight indicating pointer l9 rotatably carried on spindle it. This pointer spindle is journaled in a frame 22 fixedly mounted in the dial head unit and which supports pivotally the load counterbalancing pendulums 23 that are caused to swing upward and outward inFig. 1 responsive to the downward "pull of a weighable load on draft rod 93 transmitted through flexible ribbons '24. In

the aforesaid patent there is fully illustrated and described a mechanism 25 that transmits movement from pendulums 23 to the pointer spindle 2|.

It will be understood with reference to Fig. that the draft rod l3 extends to any suitable lever or system of levers (not shown) supporting a receptacle 4 for a load to be weighed. For the purposes of the present invention such weighable load receptacle will consist preferably of a liquid container l5 with means l2 permitting the. contained liquid to pass out of the weighable load receptacle at a regulatable rate of flow and thereby decrease the weighable l'oa'd progressively. The liquid may consist, for example, of a body of lubricating oil that is being fed to the bearings of a, motor or some other moving machine parts, or may consist of? gasoline fuel being. fed to the cylinders of an internal combustion engine.

The hub 26 of weight indicating pointer is is recessed toprovide aconical clutch face 2-! accessible at the front end of spindle 2| and is secured to the-latter by a pin 28'.

Chart H is covered and protected in conventional manner by a circular window 230i transparent material whicl'i may be a disc of glass spaced forwardly from the chart so as to form the pointer chamber 30'. This window is firmly held by meansof its peripheral edge in a mounting ring 32' retained by the bezel 33- which is re movably secured by screws 34 to the chambersurrounding barrel 35 that in turnis supported by the back plate 36- carriedfixedly on casing l6. Fig. 4- makesclear that the chart I? is. alsocarried by back plate 35' being removably secured thereto by screws 38.

In one possible form of the present improvements a circular aperture is cut in window 29 to fit and receive a round stationary bearing sleeve 3% disposed coaxiall'y' with the spindle 21 of the weighing pointer. Sleeve 39, by means of its mounting flange 4-0, is secured firmly towindow 29 by means of fastening screws 4i, each of which penetrates window 29- and has threaded engagement with mounting flange '40. A thrust washer 42 is also penetrated by screws 41 and clamped by the head of these screws. against the front surface of Window 29. Suitable gaskets '43, 43 are interposed between flange 40, washer 2, and the window 29 to prevent strain and breakage of the material of which the window may be composed if it be glass or some other brittle substance.

The forwardly elongated end of bearing sleeve 39 serves to support side-by-side solenoid wind-- ings 45 and 45 which are separated from each other by insulative washers i! and are separated from bearing sleeve 39 by insulative bushings 48 and .9 respectively. Solenoid 46 is further separated from thrust washer 42 by an insulative spacer 5! while the front face of solenoid 45 is armored by an insulative facing 52. The extreme forward end portion of bearing sleeve .39 is externally threaded at 5-3 to receive in threaded engagement therewith the apertured bearing cap 54 which clamps in place the outer race of a ball bearing 55. A similar ball bearing '56 is ,flxed in a counterbore at the rearend of the bearing sleeve 39.

Plunger shaft 58 is freely rotatable in the ball bearings 55 and '56 and is also free to slide axially with respect thereto. Coaxially with solenoids 55 and 43, shaft 58 carries a plunger armature 53 ofmagnetically attractable material, preferably of soft iron, which is shiftable from one 4 to the other of the different electromagnet fields of the said two solenoids. At its front end, plunger shaft 58 fixedly carries hand knob 6!} for turning this shaft. At its rear end and in close proximity to pointer hub 26, shaft 58 carries fixed thereon by a pin 5'1 or other suitable means the hub Bl of a marker pointer 62. which is fixedly secured on this hub by any suitabl means such as rivets 63. The rear peripheral. edge of hub 51. is chamfered at 5 to provide a conical clutch face adapted to mate with the clutch face 2? of the weighing pointer hub 25. The front peripheral. edge of hub 6! is chamiered to provide a similar conical clutch face adapted to mate.- with a stationary conical brake face 56 formed in the rear end of stationary bearing sleeve 39. The-marker pointer s2 is longer than is the weight indicator pointer is and sweeps over a different series of graduations 8i.

A conductor leading to one end of solenoid winding 45 is indicated at 68. A similar Conductor $9 is connected to. one end of the other solenoid' #56.

of both said solenoid windings. In Fig. 8 circuit connections are. shown. including the three above described conductors and-showing that co ductor H1 may connect toonel-ine ll of the mains while the conductors 6.8. and 63, terminate respectively at two switch contacts [2 and 13, one of which is always open. As indicated diagrammatically by the. two,.w.ay current switching arm 1.4, either of contacts; l2 and; 13 may selectively be connected to the other'line E5 of the mains so that by means of this switch 14 either one or the other, but not both, of solenoids 45, Mi may individually be energized electrically.

In one way of practising this invention it is the purpose to, shift, current; switching arm "M into electrical contact. with circuit terminal it for a definite limited interval; oftime thereby to energize solenoid 46. for the duration. only of such accurately known lapse of time. Accurate timing of this interval may be accomplished manually by referring to some conventional form of time piece or to a stop Watch or the, like as a timing guide as to when to shift the switch i to make and to break contact with terminal 73. Automatic time controlled operation of this current switching arm '14, or its current switching equivalent, may be found to be more convenient. For this purpose use may be made a time controlled switch to serve the purposes of switch 15. A preferred type of time controlled switch will be capable of being pre-set to predetermine a definite interval of time that will elapse between making and breaking of contact between ls-l t. Such time switches are available in many makes and kinds. They may be of the type which automatically both makes and breaks contact between 14 and 13 at pro-set. times, or they may be of the type which automatically only breaks contact a pre-set time. after such contact has manually been made. They may incorporate doubleh throw or two-way switches adapted simultaneous- 1y to make one circuit and break another circuit and then vice versa, as is the function of switch arm 14 in Fig. 8. with respect to the two different circuit terminals 12 and f3, respectively, where there are two solenoids to be energized alternatc- 1y. The time movements of such time controlled switches may be powered by escapement retarded spring driven motors or by small synchronous electric clock motors. Such timing movements may be started by direct manual actuation or A conductor 10 divides into two leads which connect. respectively to the opposite ends through electrical effects translated from a remote point of control. It will be needless to describe in fuller detail the many kinds of time controlled switches that can be used for the purpose of measuring or automatically determining the definite length of time that solenoid 46 shall remain energized through the action of switch 14. One example of a time controlled switch of the double-throw or two-way type capable of serving the purpose of switch i4 is shown in U. S. Patent No. 1,984,204, granted December 11, 1934. Particular reference may be made to Figs. 30 to 33 of the drawing of said patent wherein a conductor designated Y is shown which leads current to both of two oppositely acting solenoids, comparable to applicants conductor 1Q herein, and two other conductors X and Z are shown which-lead current separately to said respective soleno ds comparable to applicants conductors 68 and. 6!! herein. In a normal or starting condition as shown in Fig. 30 of said patent (Fig. 10 herein), a circuit through only one of the two solenoids is made. Upon manually turning a time setting and switch control handle 1'! shown in said patent and herein from its position in Fig. 10 herein to its position in Fig. 11 herein, the current is thereby manually switched from that solenoid to a second oppositely acting solenoid. At the end of a preset definite interval of time, contact 23 of the patent becomes automaticallyswitched back to its position shown in Fig. of the patent (Fig. 10 herein) and restores current to the first solenoid, at that time leaving the second solenoid again out of circuit. Figs. 1'7 to 20 of the same patent show a different switching and circuit ar rangement for placing two alternately energizable circuits A and B under interval timed control.

The whole operation may first be described without special regard to whether the current switching action of switch '14 is to be timed manually or automatically. In the example herein given the weighing graduations E8 of Fig. 3, chosen merely for purposes of illustration, indieats a total dial chart capacity of 75 pounds. There is an additional series of direct reading rate-of-depletion graduates 6'! marked for registering decreases in the weight of the scalesupported load at as high a rate as 4590 pounds per hour. Graduations it are spaced and marked to cooperate with the ordinary weight indicating movement of pointer is and certain of the rateof-depletion graduations 5? fall on common radial lines of the chart with certain of the weight indicating graduations 18. For example, in the particular combined series of graduations herein employed to illustrate the broad principle of the invention, the rate-ofdepletion graduation marked 60 designates 60 pounds decrease in weight of load per hour-J This falls in radical alignment on the chart with the weight graduation marked 74 pounds. Rate-of-depletion graduation marked "126 pounds per hour aligns with weight graduation '73 pounds, etc. Since in the present instance the progressive load change whose rate is to be registered directly against graduations 53' by the marker or excursion pointer 62 constitutes a depletion or decrease in weight, pointer 19 will progress counterclockwise as the load weight progressively lessens. For this reason the rate-of-depletion graduations are numberedadditively in a counterclockwise direction If the load changeconstituted an increase in weight, indicia 61 would be'numbcred additively in a clockwise direction.

For example of a practical use, it may be assumed that a freely weighable receptacle 15 containing 69 pounds of lubricating oil rests on the platform [4 of the weighing scale and hence exerts a pull on draft rod 13 which lifts the automatic load counterbalancing pendulums 23 sufficiently to swing the weighing pointer is nearly a full circle clockwise from top center, or noload position, to a position of register with the 69 pound mark on the chart graduations l8 as shown in Fig. 1. Through a suitably regulatable form of liquid outlet such as faucet l2, which must not interfere with accurate weighing of the scale-supported receptacle, it will be assumed that the lubricating oil is permitted to drain out of the scale-supported receptacle at some unknown rate of flow consumed in feeding the oil to the bearings and working parts of some motor or machine. Such continuous outflow of oil causes progressive decrease in weight of scalesupported load consisting of the receptacle and its contained oil. It is desired by means of my improved rate measuring instrument to ascertain the rate of outflow of the oil. This of course will be proportional to the rate of decrease in weight of the scale-supported load.

As the weighable load becomes depleted, weighing pointer Iii will travel counterclockwise over graduations is away from it position shown in Fig. 1. However the marker or excursion pointer 62 can at first remain undisturbed and stationary at its top center or zero position because electric switch 74, as shown in Fig. 8, is at first positioned to energize only the solenoid through the circuit i5, l4, i2, 68, 45, H3 and H, the lines H and 15 being regarded as the supply mains. Under these circuit conditions, the plunger armature '59 is urged forward, or toward the left in Fig. 4, by the magnetic attraction of solenoid 45 which while energized tends to centralize this armature in relation to the magnetic field of solenoid 45 and thus tends to pull it away from centralized relation to solenoid 46. This magnetic pull of solenoid 45 separates clutch face 64 from clutch face 2'! and maintains the brake face pressed against the brake seat 66 thereby to exert friction which holds excursion pointer 62 yieldably stationary in any rotary position.

Exactly when weighing pointer l9 starts moving or later while it is moving counterclockwise, switch M may be shifted from contact with circuit terminal 12 to contact with circuit terminal 13 thereby deenergizing solenoid 45 and simultaneously energizing solenoid 45 through the circuit l5, I4, 13, 69, 46, 1B and H in Fig. 8. Thereupon the magnetic pull of solenoid 45 on armature 58 in a forward direction ceases and in its place there is set up by the electromagnetic attraction of solenoid 46 a rearward pull on said armature, toward the right in Fig. 4. This rearward pull separates the braking surfaces 65, 66 and at the same instant thrusts clutch face 64 against clutch face 21 causing excursion pointer 62 to be picked up and impelled counterclockwise in unison with the counterclockwise traveling weighing pointer l9, so that the angle of separation between these pointers, as appearing in Fig. 1., remains a constant throughout the travel of both pointers in unison from their positions shown in Fig. 1 through their positions shown in Fig. 5 to, say, their positions shown in Fig. 6. The latter position is assumed to be reached by the two pointer exactly at the expiration of the definite known tim i t rval her inb fc e eferred to and hich t desi ed may be automati aliv d ermine a her in i re i u e At his oint sw tch 14 i shi t ba o i s ri inal pesition shown Fig, 8 thus again deenersizi o enoid 4 and r ene sizi Solenoid 45 which transfers the hub E5! of excursion pointer 62 away from impellable engagement with hub 25 and restore it to stationar braked engagew th nam bearing leev Excursion pointer 62 thus becomes instantly arrested in its position shown in Fig. 6 while the weighing pointer is is -left free to continue its counterclcclrwise travel to, say, top center or zero positien as shown in Fig. 7 as the weight of the oad on nu s t d crease n l th a e-sur parted receptacle becomes entirely emptied of oil. Marker pointer 62 can be reset for a subsequent time controlled rate measuring excursion of marker pointer 62 by grasping hand knob iii} and turning this pointer clockwise back to its top center or zero position against the yielding resistance of the iriction brake faces 65, 66. In zero position pointer 62 can conveniently be arrested by stop iii. The usual tare beam (not shown) in the weighing scale mechanism can be utilized in conventional manner to offset the weight of the eempty oil receptacle employed.

In the'operation which has been described it is seen that the weighing pointer is permitted to move over any random distance within its range of weighing travel in correspondence as usual with progressive change or decrease in load weightand that at any random point throughcut this entire range of travel the excursion pointer '62, may instantly be coupled to the weighing pointer is and may at such random point begin to travel in unison with the weighing pointer for some definite chosen interval of ime In carrying out such practical example of use one minute may conveniently be chosen as the definite time interval during which the marker pointer 82 shall be caused to travel in unison with the weighing pointer it. If this time limited excursion-of the markerpointer away from top center or zero position begins when the weighing pointer is exactly at the 69 pound mark as in Big. 1 and ends when the marker pointer is left stationed as in Fig. 6, the marker pointer will be found resting in register with one of the graduations 5? which is marked'to designate, say, 2785 pounds per hour which will have been the average rate of decrease in weight of the weighablc load during the one minute excursion of the marker pointer. Since the marker pointer performed its excursion in unison with the travel of, th weighing pointer both pointers traveled thr :h the same number of degrees of rotation dur i the one minute time interval. It foliows that the marker pointer traversed /r500 or oi sec degrees, or 216 degrees of travel. Therefor the d r a e in load, measur d in pounds. was during this same one minute interval taxia pounds or- 45 pounds.

Without the benefits oi this invention it would have been required to observe that the weighing pointer in one minute moved between two points alo g the series or weighing g-raduations #8 whose dif' rential equalled 45 pounds, and then from this data to compute the rate or load change by multiplying 45. pounds by '60 in order to find the number of pounds of load change, namely, 270% pounds per hour. Lost, time and labor and great liability tov manual error in observation and ro cording would be occasioned. By means of these improvements no attention of the operator is necessary beyond once pushing a button, or once turning the time starting handle of a time controlled electric switch whenever a measurement of rate of fiow is to be started. After that all the operator has to do is to return at any convenient time and observe the direct reading of the indicium of graduations ill at which the marker or excursion pointer 62 has automatically been left stationed. From this is immediately known without computation or loss of time the average rate of load change in terms of pounds per hour that has taken place during the particular time interval of the test, Weighing grade uations 58 need be referred to only in order to know whether the scale-supported receptacle cQnn tains enough oil tor the purposes of the test. Otherwise graduations i8 and pointer is could be eliminated entirely with loss of the ability to read the scale measured weight of load since the present improvements make it unnecessary to know the amount of load weight in order to determine rate of load change.

These and many other modifications are within the scope of constructions contemplated and in! tended to be covered by the following claims whose terms are therefore not limited in meaning to the particular forms of the invention herein disclosed.

I claim:

n a m er for regist ring rat of han e in a magnitude oi weight, the combination of, an excursion performing rate of change indicator normally free from motivating bias, means to set said unbiased rate indicator at a constant initial locus, instrumentalities operative to measure a changing magnitude of weight whose rate of change is to be registered by said indicator, a weight measuring pilot connected to travel in response to said instrumentalities over distances proportioned to change occurring progressively in. said magnitude of weight, a mechanical connection operatively associating said indicator and said pilot operative upon occasion to cause said unbiased indicator to perform an unresisted excursion of travel away from said locus definitely and continually proportioned in extent to the simultaneous travel of said pilot, means operative upon said connection in a manner to disable the latter and thereby disasscoiate said indicator from said pilot when the former is either at or away from said locus thereby to enable said indicator to dwell free of motivating bias at times while said pilot continues to travel in response to continuing change in said magnitude of weight.

2. In a meter for registering rate of change in a magnitude of weight, the combination of, an excursion performing rate of change indicator normally free from motivating bias, means to set said unbiased rate indicator at a constant initial locus, instrumentalities operative to measure a changing magnitude of weight Whose rate of change is to be registered by said indicator, a weight measuring pilot connected to travel in response to said instrumentalities over distances proportioned to change occurring progressively in said magnitude of weight, a mechanical con nection operatively associatin said indicator and said pilot operative upon occasion to cause said unbiased indicator to perform an unresisted excursion of travel away from said locus definitely and continually proportioned in extent to simultaneous travel of said pilot, means operative upon said connection in a manner to disable the latter and thereby disassociate said indicator from said pilot at selective times, and mechanical detentive means operatively associated with said indicator in a manner to arrest the latter at said selective times while said pilot continues to travel in response to continuing change in said magnitude of weight.

3. In a rate meter, the combination defined in claim 1, together with plural electromagnets located at a common side of and operatively related to the said mechanical connection in a manner to control therethrough the association and disassociation of the said indicator and the said pilot.

*1. In a rate meter, the combination defined in claim 2, together with plural electromagnets located at a common side of and operatively related to the said mechanical detentive means in a manner to control the arresting thereby of the said indicator.

5. In a rate meter, the combination, defined in claim 2, together with an electromagnet located at one side of the said mechanical connection and the said detentive means and operatively related to the former in a manner to control therethrough the association and disassociation of the said indicator and the said pilot, and another electromagnet located at the said side of the said mechanical connection and said detentive means and operatively related to the latter in a manner to control the arresting thereby of said indicator.

6. In a rate meter, the combination defined in claim 1, in which the said means operative upon the said connection includes hand set time controlling mechanism acting automatically to disable the said connection for disassociating the said indicator from the said pilot at the expiration of a predetermined interval of time,

7. In a rate meter, the combination defined in claim 2, in which the said means operative upon the said connection includes hand set time controlling mechanism acting automatically to disable said connection for disassociating the said indicator from the said pilot at the expiration of a predetermined interval of time, and in which the said detentive means is operably related to said time controlling mechanism.

8. The combination of, automatic load counterbalancing apparatus, means to apply loads of progressively varying weight to said apparatus in a manner to prevent said apparatus from resting in a state of balance with the load, a pilot con nected to be impelled progressively by said apparatus over distances continually proportional to changes of weight in said load, a movable marker normally free of motivating bias, movement transmitting mechanism connecting said unbiased marker impellably to said pilot upon occasions, and means selectively to disable said mechanism so that said unbiased marker can stand at rest while said pilot travels.

DONAL J. DWYER.

REFERENCES CITED The following references are of record in the file of this patent:

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